/*
 * Copyright 2004 - 2013 Wayne Grant
 *           2013 - 2021 Kai Kramer
 *
 * This file is part of KeyStore Explorer.
 *
 * KeyStore Explorer is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * KeyStore Explorer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with KeyStore Explorer.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.kse.utilities;

public class ArrayUtils {

	private ArrayUtils() {
	}

	/**
	 * Concatenate two byte arrays.
	 *
	 * @param a
	 * @param b
	 * @return Concatenation of a and b or empty byte array if both values are null
	 */
	public static byte[] add(byte[] a, byte[] b) {

		// graceful handling of null values
		if (a == null) {
			if (b == null ) {
				return new byte[0];
			} else {
				return b;
			}
		}
		if (b == null) {
			return a;
		}

		byte[] result = new byte[a.length + b.length];
		System.arraycopy(a, 0, result, 0, a.length);
		System.arraycopy(b, 0, result, a.length, b.length);
		return result;
	}
}
